If for example Pikachu learns Electra Ball in V Gen, but you have a Pikachu in IV Gen then after pokeshifting it will be able to learn Electra Ball (through level up or relearning for Heart Scale). I hope this is what you were asking, lol. Same for TMs - Scald is a V Gen move but my Suicune learnt it via TM - after pokeshifting, ofc.